This is a U.S. National Phase Application Under 35 USC 371 and applicant herewith claims the benefit of priority of PCT/AU00/00486 filed May 19, 2000, which was published Under PCT Article 21(2) in English and Application No. PQ 0509 filed in Australia on May 21, 1999 and PQ 4395 filed in Australia on Dec. 1, 1999
The invention relates to a control system for a gate or door which is operated by an automated operator.
Whilst the following description is in terms of rolling door assemblies, it will be readily apparent that the invention relates to any type of door or gate which is opened and closed using an automated operator.
It is commonly known that the load experienced by a rolling door over its normal up and down travel path varies considerably. Typically, conventional door operators have only one overload trip point setting for each direction of door travel. This trip point is incorporated to interrupt the direction of travel of the door or gate where resistance to the movement of the door or gate exceeds that point. This conventional trip point setting must be adjusted for the heaviest section of the door""s travel. That is the section over which the load is greatest. As the trip point is in effect adjusted to a level to account for the worst situation in the travel path, consequently a heavy load is needed to trip the door in sections where the loads are lighter.
For example, the trip point may be incorporated into the door mechanism to avoid the door or gate operator becoming overloaded by an obstruction in the door""s path preventing its movement. Likewise, for safety reasons the conventional door is required to reverse its direction of travel if such an obstruction occurs such as a person being in the door travel path. Clearly, the approach of setting the trip point dependent upon the heaviest load may result in injuries to a person who obstructs the door in its travel.
It is also commonly known that the load experienced over the travel of the door alters over time and with usage. Conventional door operators typically have an overload trip point which, once set, is fixed. Consequently, the door operator is unable to adjust to variance in normal door resistance load over time. This manifests itself as poor overload sensitivity after some time. Such manifestations may include a door which fails to shut or open as the door will travel until the load trip point is exceeded and the door reverses. Conversely, the loads may become so light that considerable pressure will be applied to an obstruction before the trip point is exceeded and the travel direction of the door reversed.
It is therefore an object of the invention to provide a control system which ameliorates one or more of these problems.
According to one particularly preferred form of the invention, there is provided a control system for a door or gate which is movable between an open position and a closed position by an automated operator, comprising:
(a) a door travel organiser which divides the door travel into a plurality of segments and each segment into a plurality of sections;
(b) a sensor to sense, at each sector, the resistance of the door or gate against opening and closing whilst moving between the open position and the closed position over a predetermined number of open-close cycles, and to generate at least one signal representative of that resistance in each segment over the open-close cycles;
(c) a recorder connected to the sensor to receive each representative signal and to store such a signal;
(d) a comparator to compare each signal with a resistance trip point set for each segment and generate a resistance profile for the door or gate over an open-close cycle of the door or gate;
(e) a calculator to calculate the resistance trip point for the door or gate for each segment based upon the highest resistance encountered in any sector of that segment; and
(f) a controller to receive each trip point and set each trip point as a threshold for each segment such that if resistance of the door or gate sensed by the sensor in any sector exceeds that threshold for that segment, the movement of the door or gate is interrupted.
Typically, the resistance of the door or gate is sensed by monitoring the speed of the door over the open-close cycle. It is thought that speed is representative of that resistance. As such, by recording the speed profile of several open-close cycles and averaging the minimum speeds of each segment, the trip point can be set for each segment at a value which is more closely aligned to the characteristic resistance for that segment.
Consequently, in any one segment, if an obstruction is encountered, only the trip point set for that segment need be exceeded to cause interruption of the movement of the door or gate.
In another preferred form of the invention the control system further comprises an alarm which is operable upon the controller interrupting the movement of the door or gate.
In another form of the invention the control system further comprises an alarm which is operable when the resistance profile of the door or gate exceeds predetermined maximum profile points. In this way, if the resistance of the door or gate builds up over time which is a typical characteristic of doors, an alarm may be provided to indicate that maximum resistances are being approached. This will indicate that servicing of the door or gate is needed.
Preferably, the resistance profile of the door or gate will be established by monitoring enough open-close cycles so that any abnormal representative signals do not cause aberrant trip points to be set. In this respect, the number of cycles is expected to be at least 8.
Suitably the control system comprises a remote trigger which operates to ensure that the door or gate cannot be operated by a remote control until the resistance profile of the door or gate has been established.
Preferably, the control system further comprises an immobiliser to immobilise the door or gate if the signal for any segment exceeds the trip point set for that segment by a predetermined value. In this arrangement, if the variation in this signal is exceeded by, for example, 10% or 20%, which means that the door or gate and/or operator are in danger of failing, the immobiliser causes the mechanism to stop. Preferably, the system further comprises another alarm which is activated if the immobiliser is activated.
Typically, the alarms referred to above may be a visual and/or audible display such as a series of lights or sounds. It is possible to have a single alarm which produces the function of all the alarms mentioned above. For example, the first condition, when the notification signal is received, may be displayed by illuminating two of the LED""s. When the immobiliser is active, then all four of the LED""s may be displayed.
The control system may also include a set up facility. The set up facility may include means for adjusting a predetermined resistance value exerted by a motor on a door or gate at which the immobiliser causes the mechanism to stop. The adjustment means may be such as to allow an installer to vary the predetermined resistance value at the site where the control system has been installed. The set up facility may include means to run the door through an open and close cycle so that the normal operating resistance parameters of the door installed at the site may be sensed and used to set a predetermined resistance value for operation of the door.
The control system may also include a default safety resistance value. This may be preset in the factory. The set up facility may also include means to alter the default safety resistance value on site. The magnitude of the default safety resistance value may be the primary determinant for immobilising the door, regardless of the setting of the predetermined resistance value.
In another preferred form of the invention there is provided a method of controlling a door or gate which is movable between an open position and a closed position by an automated operator, comprising the steps of:
(a) dividing the door travel into a plurality of segments and subdividing each segment into a plurality of sectors;
(b) sensing, at each sector, the resistance of the door or gate against opening and closing whilst moving between the open position and the closed position over a predetermined number of open-close cycles, and for each segment generating at least one signal representative of the sector in that segment having the highest resistance over the open-close cycles;
(c) recording and storing each representative signal;
(d) generating a resistance profile of the segments for the door or gate over an open-close cycle of the door or gate;
(e) calculating a resistance trip point for the door or gate for each segment based upon the resistance profile;
(f) setting each trip point as a threshold for each segment; and
(g) for each segment of movement of the door or gate comparing such threshold to the resistance of the door or gate in the sectors of that segment and interrupting the movement of the door or gate if that threshold is exceeded.
The resistance profile may suitably be generated on the basis of the running average of the lowest sector speed for each segment.
According to another independent form of the invention, there is provided a diagnostic system for a door or gate which is movable between an open position and a closed position by an automated operator, comprising:
(a) a sensor to sense, at predetermined intervals, the resistance of the door or gate against opening and closing whilst moving between the open position and the closed position over a predetermined number of open-close cycles, and to generate at least one signal representative of that resistance in each segment over the open-close cycles; and
(b) a recorder connected to the sensor to receive each representative signal and to store such a signal.
Typically, the resistance of the door or gate is sensed by monitoring the speed of the door over the open-close cycle. It is thought that speed is representative of that resistance. As such, by recording the speed profile of several open-close cycles and averaging them, the trip point can be set for each segment.
Using this diagnostic system, it is possible to produce a representation (eg graphs) of the resistance in door or gate travel over the open-close cycle. These can be used to identify sections of the door or gate travel of significant resistance and by comparison, determine the door geometry which provides the most efficient load profiles. This information may also be used to identify areas in the door mechanism which may require servicing. Especially if the door or gate resistance profile is built up over a period of the life of the door. This means that preventative maintenance may be carried out rather than the repair scenario which is common now.
Typically the diagnostic system will be in two parts. The first will be a data storage device affixed to the door or gate controller and provided with a data outlet port. The second part will be a hand held computer with a data input port compatible with the data output port. The data will be down loaded into the hand held computer. Comparisons with other earlier down loaded data for the same door or gate may be made so that resistance changes may be considered. Similarly, that data may be compared to information received on the resistance characteristics of other doors and gates. This enables servicing to be carried out and simultaneously the results of the servicing in terms of resistance adjustment may be monitored.
In yet a further form of the invention there is provided a control system for a door or gate which is movable between an open position and a closed position by an automated operator, the automated operator including a drive motor, the control system comprising:
a) a pulse encoder associated with said motor generating pulses at a frequency proportional to the motor speed, with the number of pulses generated being an indication of the relative position of the door or gate, such that the pulse encoder is able to provide an indication of the resistance of the door or gate against opening or closing whilst moving between the open and the closed position over a predetermined number of open-close cycles, and thereby generates at least one signal representative of that resistance in each sector over the open-close cycles;
b) a door travel organizer arranged to act upon the signals provided by said pulse encoder, the organizer dividing the door or gate travel into a plurality of segments, and each segment into one or more sectors, each sector being equivalent to the interval between two encoder pulses;
c) a recorder connected to the sensor to receive each representative signal and to store such a signal;
d) a comparator to compare each signal with resistance trip point set for each segment and generate a resistance profile for the door or gate over an open-close cycle of the door or gate;
e) a calculator to calculate the resistance trip point for the door or gate for each segment based upon the highest resistance encountered in any sector of that segment; and
f) a controller to receive each trip point and set each trip point as a threshold for each segment such that if resistance of the door or gate sensed by the sensor in any sector exceeds that threshold for that interval, the movement of the door or gate is interrupted.
Each segment may thus comprise a single sector, such that the resistance trip point for each segment is based upon the resistance encountered in that one sectors.